Means for clinching nuts on metal panels



July 16, 1957 J. F, NEWCOMB mus FOR cpmcumc NUTS on METAL PANELS FiledApril s, 1956 2 Sheets-Sheet 2 INVENTOR FIG. 8

.P m L w E v. N m E m MM United States Patent MEANS FOR CLINCHING NUTSON lVIETAL PANELS This invention relates to apparatus and the method ofpunching flange nuts through a metal panel and clinching the nut on theback of the panel all in one stroke. In

my prior application, Serial No. 386,224, filed October 15, 1953, I havedescribed a method and apparatus for doing this work. The presentinvention is an improvement on the apparatus and method described inthis prior application.

In the prior application a punch and die are described and shown inwhich the die is provided with a plurality of channels with projectingnubs which project in the central opening of the die. A punch isprovided with a permanently magnetic core which holds a flanged nutwhich is fed into the punch by means of a chute. The punch with the nutcomes down on the die, and the non flanged or body portion of the nut ispressed through the metal panel and into the central opening of the die.The edges of the lands between the channels shear off a portion of thepanel, and the projecting nubs cut into the body of a nut and roll upportions of the nut into the channels thereby staking the nut to theopposite side of the panel.

It is the purpose of the present improvement to have portions betweenthe spurs or stakes that are pressed out of the panel, pressed upagainst the body of the nut to seal the nut against the rear of thepanel to make a liquidtight joint.

To this end I provide a special form of nut in which the non-flanged orbody of the nut is tapered backward from the outer edge of the body soas to provide a dovetail recess in which the portion of the panelbetween the stakes can be pressed into this recess by means of bosses onthe die around the central opening.

Referring to the drawings:

Fig. 1 shows a portion of a panel with a clinched nut in place.

Fig. 2 is a perspective of a nut.

Fig. 3 is a plan view of the die.

Fig. 4 is a plan view of the punch.

Fig. 5 is a longitudinal section through the punch showing a nut inelevation.

Fig. 6 is a fragmentary longitudinal section through the die.

Fig. 7 is a fragmentary longitudinal section through the punch, the die,the nut, and a portion of the panel.

Fig. 8 is a fragmentary longitudinal section through the same showingthe nut in elevation.

Fig. 9 is a fragmentary section through the same parts showing the nutas it passes through the panel and about to be acted upon by the nubs ofthe die.

Fig. 10 is a similar view showing the nut as it has been acted upon bythe nubs of the die to roll up spurs from the body of the nut.

Fig. 11 is an elevation of the punch.

1 shows the flanged nut provided with a non-flanged body portion 2 whichis tapered backwardly at 3 to form a dove-tail like groove. The punch 4has a central cavity 5 with a permanent magnetic core 6. The nuts arefed continuously into the central cavity through the side opening 7 bymeans of a chute (not shown) in which the nuts slide into the cavityeither by gravity or are projected therein mechanically. The underdie 8is provided with channels 9 which have tongues or nubs 10 projectinginto the central cylindrical opening 11 of the die.

When a nut is fed into the cavity of the punch, the punch then comesdown and presses the nut through the panel 12 as shown in Fig. 9,shearing off the slug 13 from the panel and turning the lips 18 into thechannel. As the nut is pressed clear through the panel and down into thedie, the nubs 10 of the die bite into the body of the nut and turn thespurs 14 into the channel thereby staking the nut to the back of thepanel as shown at 15 in Fig. 1 and at 16 in Fig. 7.

This much of the apparatus and method is claimed in my priorapplication. The present improvement consists in providing the dove-tailrecess between the end of the body of the nut and the flange andproviding the sharp bosses 17 on the upper face of the die between thechannels. These bosses strike the edges of the opening in the panel andpress the material of the panel between the spurs into the dove-tailrecess of the nut and thereby seal the nut to the rear of the panel andmake a liquid-tight joint at these places.

The body of the nut is shown with a truncated cone or back taperingetfect, and the cross section is a circle. This is the easiest way tomanufacture the nut, but obviously the body of the nut could have adifferent cross section. Furthermore the recess or groove might be madein some other way than back tapering the body of the nut.

I claim:

1. A punch and die for punching out a slug in a metal panel by means ofpressing a portion of a flanged nut through the panel and for also inthe same stroke staking the nut to the rear of the panel and pressingthe edges of the panel portions between the staked portions into agroove in the body of the nut, the said punch provided with means forreceiving and holding a flanged nut in a portion of the punch, and thedie provided with a central opening and having on its top surface radialchannels with sharp nubs on the ends of the channels projecting into thecentral opening which is arranged to receive the nonflanged body of thenut when the punch comes down against the die and shears a slug out ofthe panel, and the said nubs turning over portions of the body of thenut into the channels to thereby stake the nut to the opposite side ofthe panel when the nut is pressed home, and said die provided betweenthe channels with a narrow, upstanding boss which presses the materialof the panel between the stakes into the groove in the body of the nutto thereby seal the nut to the back of the panel.

2. The combination claimed in claim 1 in which the groove is formed byback tapering the body of the nut.

3. The combination claimed in claim 1 in which the body of the nut iscircular in cross section.

4. The combination claimed in claim 1 in which the body of the nut iscircular and the groove is formed in the body by back tapering.

References Cited in the file of this patent UNITED STATES PATENTS262,189 Trageser Aug. 1, 1882 521,825 Shipe June 26, 1894 1,610,664Ellison Dec. 14, 1926 1,796,852 McDonough Mar. 17, 1931 2,187,647 DoubleJan. 16, 1940 2,593,506 Wales Apr. 22, 1952 2,652,942 Muchy Sept. 22,1953 2,707,322 Strain May 3, 1955

